1. Field Of The Invention
This invention relates, in general, to a device for aiding maintenance of a semi-automatic or fully automatic electromechanical installation and, more particularly, to a device for supervising the operation of independent electromechanical installations such as lifts, escalators, elevators or the like; moving sidewalks; power distribution stations; and air conditioning or ventilation stations or the like where operation is controlled either by a conventional wired logic automatic system of the relay monitoring and control cabinet type or by a programmed logic automatic system of the industrial programmable controller type.
2. Description Of Related Art
Since electromechanical installations, such as those listed above, operate either semi-automatically or fully automatically, they must be supervised continuously. In practice, a general distinction is drawn between two levels of supervision regardless of the type of installation: (1) operational supervision which is usually provided locally by operators responsible for all or part of the operation of the installation; and (2) technical supervision which is provided by maintenance personnel responsible for repairing or maintaining the installation.
For these two supervision functions to be accomplished, supervising devices are used which automatically transmit to the operators all particular about the operation of the installation. Devices for aiding maintenance are also used which operate to acquire and impart information enabling the maintenance personnel to do their work accurately and rapidly.
Since maintenance centers are usually geographically remote from the installations, it has become necessary to transmit the information over a distance. This has been done by means of special circuits extending to a computer or by special telephone circuits extending to a data processing terminal.
Some known facilities provide the above two supervision functions simultaneously. For the sake of safety these facilities should use special transmission lines extending to a central computer which interrogates the installations constantly. These known facilities require complex infrastructures and rapidly become saturated when a large number of installations are supervised There are also supervising systems which automatically remote-transmit information over the public telephone system. However, these simple and less expensive systems do not offer the safety guarantees required for industrial use. The simultaneous performance of the two supervision functions, therefore, makes it necessary to use either costly and elaborate facilities or unreliable low-performance facilities.
In view of safety requirements and the large number of electrical installations which are maintained simultaneously, it has been proven essential that the two supervision functions be carried out completely independently of one another.
French Patent Application No. 2,564,651 in the name of SPIE-BATIGNOLLES describes an electronic interface facility for the remote monitoring and control of electronic power distribution boards. The system is connected to a control or management system. The interface system uses a central microprocessor unit connected by a standard quad circuit to maintenance equipment. However, this system is used specifically for power distribution boards and is not adapted for the remote technical supervision of a wide variety of electromechanical installations.
It is the object of the present invention to simplify and generalize the use of these known systems and to make possible technical supervision of any semi-automatic or fully automatic electromechanical installation by means of a device for aiding maintenance using the public telephone system and connectable to an existing installation. Another object of the invention is to improve the operating quality of such installations, the working conditions of maintenance personnel, and maintenance methods.